Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references). Also available on the Internet.

Made available in DSpace on 2016-08-10T10:31:07Z (GMT). No. of bitstreams: 1 MARCOS ALVES DA SILVA.pdf: 1775464 bytes, checksum: e75c1a592914214c0e8e845737a1ed64 (MD5) Previous issue date: 2009-09-29 / Aquaculture activity, that s a source of protein with low cost, fills your space every day. Thus, there is an increase in water use which has caused major losses of this natural resource, when used irrationally. Soil variables should be studied, as instruments to minimize these losses, encouraging the rational use of these natural resources. This test was conducted in a Yellowish-red clayey Latosol in deep Nursery excavated for aquaculture aimed to evaluate three repetitions of soil permeability (k) and four repetitions of the density (SD) and total soil porosity (TP) under different levels of compression: uncompressed soil (SN), compacted soil with three (CS3), six (CS6) and nine (CS9) footfalls, respectively, of the compactor drum and three footfalls of this compactor on mixture of soil-cement at a rate of 6.6% (SCC). The witness was the native soil removed from the trench 1.5 m deep. Was concluded that the Tukey test (5%), the variables SD and TP showed significant differences between the treatment SN and treatments CS3, CS6, CS9 and SCC was statistically equal the treatment CS3, CS6, CS9 and SCC when compared with each other; for the variable K, showed a significant difference the treatments SN, CS3 and CS6 was statistically equal the treatments CS9 and SCC, considering the cost of treating SCC as a 100%, the treatment CS9 was equivalent to 7% of this cost, demonstrating its economic viability. / A atividade aquícola, por se tratar de uma fonte de proteína de baixo custo, vem ocupando seu espaço a cada dia. Com isso, há um aumento na utilização da água o que tem gerado maiores perdas desse recurso natural, quando usado de forma irracional. Variáveis do solo devem ser estudadas, como instrumentos para minimizar essas perdas, favorecendo o uso racional desses recursos naturais. Esse ensaio foi realizado em um Latossolo Vermelho Amarelo argiloso em fundo de viveiro escavado para a aqüicultura e teve como objetivo avaliar três repetições da permeabilidade do solo (k), e quatro repetições da densidade do solo (DS) e da porosidade total do solo (PT) submetidos a diferentes níveis de compactação: solo sem compactação (SN); solo compactado com três (SC3), seis (SC6) e nove (SC9) passadas, respectivamente, do compactador de percussão e ainda três passadas do compactador de percussão sobre a mistura de solo-cimento na proporção de 6,6% (SCC). A testemunha foi o solo natural retirado em trincheira a 1,5m de profundidade. Conclui-se que pelo teste Tukey (5%), as variáveis DS e PT apresentaram diferença significativa entre o tratamento SN e os tratamentos SC3, SC6, SC9 e SCC sendo estatisticamente iguais os tratamentos SC3, SC6, SC9 e SCC quando comparados entre si; para a variável K, apresentaram diferença significativa os tratamentos SN, SC3 e SC6 sendo estatisticamente iguais os tratamentos SC9 e SCC; considerando o custo do tratamento SCC como 100%, o tratamento SC9 foi equivalente a 7% desse custo, demonstrando sua viabilidade econômica.

Partial-infiltration permeable pavement (PP) systems provide environmental benefits by increasing infiltration, attenuating storm flows and improving stormwater quality. This thesis focuses on the performance and operation of partial-infiltration PP systems over low permeability soil in Ontario. Three PP, AquaPave®, Eco-Optiloc® and Hydromedia® Pervious Concrete were monitored over two years and their performance was evaluated relative to an impermeable Asphalt control. Field data was collected from the Kortright PP pilot parking lot in Vaughan, Ontario. Through the use of restrictor valves on underdrains the PP systems were shown to provide substantial hydrologic benefits by eliminating stormwater outflow for rain events less than 7mm, reducing peak flows by 91% and reducing total stormwater volume by 43%. Stormwater quality was analyzed for winter and non-winter seasons. The PP were shown to greatly reduce the concentration and total loading of suspended solids, nutrients, hydrocarbons and most heavy metals. Some water quality data, such as pH, K, or Sr levels, indicate that the quality of PP effluent will change as the system ages. Study of PP sample boxes at the University of Guelph highlighted the role that construction materials have on effluent quality and showed that pollutants introduced by the pavement and aggregate are almost entirely in a dissolved form and decline very rapidly after a season of exposure to rainfall. Benefits to water quality were sustained during winter months. The partial-infiltration PP systems were shown to provide buffering of Na and Cl concentrations. Small and large-scale maintenance practices for PP systems were investigated. Small-sized equipment testing found that vacuum cleaning and pressure-washing have good potential to improve infiltration capacity. Testing of full-sized streetsweeping trucks demonstrated that permeability can be partially restored on PICP by suction-based sweeping. Vacuum-sweeping was beneficial on a PC pavement which had experienced large permeability losses. Results of this study indicate that partial-infiltration PP systems can be effective measures for maintaining or restoring infiltration functions on parking lots and other low volume traffic areas, even in areas with low permeability soils.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-10-02T15:59:06Z No. of bitstreams: 1 ADEMILSON MONTES FERREIRA - DISSERTAÇÃO PPGECA 1976..pdf: 19885507 bytes, checksum: d1ca0c059c79f92f4c6eed90665dcfc4 (MD5) / Made available in DSpace on 2018-10-02T15:59:06Z (GMT). No. of bitstreams: 1 ADEMILSON MONTES FERREIRA - DISSERTAÇÃO PPGECA 1976..pdf: 19885507 bytes, checksum: d1ca0c059c79f92f4c6eed90665dcfc4 (MD5) Previous issue date: 1976-05 / Esta pesquisa de laboratório trata da influência do tempo de percolação e do nível de acidez da água nas características de permeabilidade e resistência de um solo vermelho do Estado da Paraíba. Amostras estaticamente compactadas foram submetidas a percolação de agua por diversos tempos (24,48,7 2 e 96 horas), suas permeabilidades medidas a intervalos de 12 horas e seus parâmetros de resistência triaxial no fim dos vários tempos de percolação. Três níveis de acidez da agua de percolação foram usados, 3,25, 7,3 e 12,4. Equipamento constituído de moldes e um multipermeâmetro de nível constante foi projetado e construído para o estudo, e uma nova técnica para saturação das amostras utilizadas. 0 equipamento usado mostrou resultados estatisticamente aceitáveis e seu uso tem a vantagem de diminuir o tempo de ensaio. O coeficiente de permeabilidade variou in versamente com o pH da água de percolação. Tempo de percola ção por fluxo unidirecional causou uma diminuição de permeabilidade para qualquer dos níveis de acidez investigado. Os parâmetros de resistência em termos de coesão total e efetiva e ângulo de atrito são afetados pela acidez da água de percolação. Os valores de C e f diminuem quando o pH é diminuído de 7,3 para 3,25. Aumentando o pH para 12,4 ocorre um decréscimo adicional nos valores de C e Ø' . É feita uma interpretação qualitativa deste fenômeno. Um estudo piloto limitado dos efeitos da secagem na resistência ao cisalhamento do solo Sapê-Mari mostrou que a secagem por 6 horas a 609C aumenta os valores de C e diminui Ø' para todas as condições de tempo de percolação e nível de pH. / This laboratory investigation deals with the influence of seepage time and levei of acidity of water on the permeability and strength behaviour of a red soil from the State of Paraiba. Specimens statically compacted were subjected to water percolation for varying times (24, 48, 7 2 and 96 hours), their permeabilities measured at intervals of 12 hours and their triaxial strength parameters at the end of the various percolation times. Three leveis of acidity of the seepage water were used, i.e, 3.25, 7.3 and 12.4. Equipment consisting of molds and a multipermeameter of constant head were designed and constructed for the study, and a novel technique for saturation of specimens employed. It is shown that the equipment used provides statistically aceptable results and that its use has the advantaje of shortening the time of testing. The coeficient of permeability was found to vary inversely with the pH of the seepage water. Time of seepage by unidirectional flow caused a decrease of permeability for any of the acidity leveis investigated. The strength parameters in terms of total and efective cohesion and angle of internai friction are noticeably affected by the acidity of the seepage water. The values of C and Ø' decrease slightly when the pH is lowered from 7.3 to 3.25. Increasing the pH to 12.4 causes a further decrease in the values of C and Ø'. A qualitative interpretation of this phenomena is oferred. A limited pilot study of the effects of controlled drying on the shear strength of the Sapé-Mari soil showed that drying 6 hours at 6 09C increases the values of C and decrease 4>1 for ali the conditions of time of seepage and pH levei.